Vehicle manufacturers test vehicles by operating the vehicles over test tracks. As a vehicle traverses the track, various parameters of the vehicle are sensed and recorded. For example, vehicle speed, shock absorber temperature, axle impact energies, and so on can be measured by sensors and recorded by a flight recorder onboard the vehicle. After testing, the data can be retrieved from the flight recorder and analyzed to assess the performance and construction of the vehicle.
Typically, to increase the diversity of road surfaces over which the vehicles are tested and to thereby promote comprehensive vehicle testing, the surface of a test track will vary around the track. For example, the surface can vary from conventional asphalt to bumps, then gravel, and so on.
It is advantageous that data obtained from dissimilar surfaces not be mixed. By not mixing the data, post-test analysis can be more rigorous and detailed in pinpointing potential design issues. Accordingly, it is desirable that the position of a test vehicle on a track be recorded along with the test data, so that the various data recordings can be correlated to the portion of the track over which the data was collected.
Unfortunately, existing vehicle position sensing systems have several drawbacks. For example, obtaining vehicle position data over time using navigation satellites is possible, but unless comparatively expensive satellite navigation systems are used, satellite systems render positional data with a precision that is insufficient for test track applications. Further, satellite navigation systems use a radiofrequency that requires line-of-sight communication be established between the satellite and the vehicle's satellite receiver, thus undesirably necessitating the use of an expensive, external antenna on the vehicle. Still further, the output of navigation satellite systems is rendered in terms of latitude and longitude, which must be converted to test track coordinates to be useful. Such conversion undesirably complicates the test analysis. Likewise, existing terrestrial position systems are expensive, and their performance is unreliable, rendering them inadequate for prolonged test track use.
Accordingly, the present invention recognizes the need to provide a low-cost, reliable vehicle position system for a vehicle test track. Moreover, the present invention recognizes that such a system advantageously should be easily maintained. And, the present invention recognizes that fixed position beacons in such a system transmit data efficiently, using a simple, low-cost, easily maintained transmitter system. Additionally, the present invention recognizes that such a system be compatible with a large number of existing vehicle flight recorders. Accordingly, it is an object of the present invention to provide a test vehicle tracking system for a vehicle test track. Another object of the present invention is to provide a test vehicle tracking system for a vehicle test track that is reliable and inexpensive. Still another object of the present invention is to provide a test vehicle tracking system for a vehicle test track that can be used with a large number of flight recorders, without requiring excessive hardware modification to either the flight recorder or the tracking system. Yet another object of the present invention is to provide a test vehicle tracking system that transmits binary data without requiring excessive signal coding hardware. Another object of the present invention is to provide a test vehicle tracking system that is easy to use and cost-effective.